what dates on the IH cents ? CW era ? 1865 and before?
-- looks flattened on both ends --might be a pounded flat on both ends bullet for use as a checker or chess game piece (say a rook /castle) almost looks like a rivet shape to me --but a lead rivet?
No not a rivet I don't think 1864 ihp a number of awesome buttons . I think I have found one of each kind of eagle button except infantry. I have navy artillery cavalry and rifleman all have been found in the same area